stlToSolid 0.5.7 · user manual

How to use stlToSolid

A guide to the four tools in the app and the Fusion 360 add-in: what each one is for, how to use it, and what every setting does, with screenshots.

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Guide · section 2Getting startedThe screen, loading a file, units and scale, picking bodies and moving around the 3D view.Tool · section 3Mesh → SolidMachined and printed parts to a clean STEP with real planes, cylinders and holes.Tool · section 4Sliced LoftCaps, handles and shells: slice along one axis and loft one smooth solid.Tool · section 5X-RayA stack of real, closed Fusion sketches between two planes, as one script.Tool · section 6BlueprintA dimensioned drawing to named parameters and a parametric Fusion script.Tool · section 7Fusion add-inMesh to Outline: the X-Ray tracing inside Fusion 360, from planes to a solid.Guide · section 8–11ReferenceThe report, running scripts in Fusion, troubleshooting and every default.

Introduction

A mesh file (STL, OBJ, 3MF and so on) describes a part as thousands of tiny triangles. That is fine for a 3D printer, but a CAD program cannot work with it: you cannot sketch on a triangle, measure a hole or fillet an edge. Fusion 360's free tier can turn a mesh into a solid, but every triangle becomes its own face, so the "solid" is just as hard to model against.

stlToSolid rebuilds the part the way a designer would have drawn it: real flat faces, real cylinders and cones, real holes. You get a STEP file you can import into Fusion 360 (or any CAD program) and design around.

stlToSolid comes as a desktop app for Mac and Windows, as a Docker container for a home server or NAS (opened in a browser), and as add-ins that run inside Fusion 360. The desktop app and the browser version are the same program with the same four tools. This manual covers all of them.

Which tool should I use?

Your part looks like…	Use	You get
A machined or CAD-designed part: brackets, plates, housings, holes, slots and steps	Mesh → Solid	A clean STEP with true planes, cylinders, cones, spheres and tori
A smooth, flowing shape that changes gradually along one direction: caps, handles, shells, bottles	Sliced Loft	One smooth lofted solid, plus a Fusion script that repeats the loft
A part you want to rebuild yourself in Fusion from cross-sections	X-Ray	Real, selectable Fusion sketches, one per slice, ready to extrude (optionally extruded into slabs for you)
No mesh at all, just a dimensioned drawing or datasheet picture	Blueprint	A parametric Fusion script (User Parameters, sketches, extrudes) and a STEP
A mesh that is already inserted in a Fusion design	Mesh to Outline (Fusion add-in)	The same X-Ray sketches, drawn straight into your design, with no file to download